


Know Thy Enemy

by notsafeforwank (comeonlight)



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Anal Fingering, Angry Edelgard, Bottom Edelgard von Hresvelg, Casually Horny Rhea, Cunnilingus, F/F, Feral Idiots, Hate Sex, I Have No Idea What's Happening Anymore, Masturbation, Mental Power Struggle, No Lube, Other Tags I Don't Know What To Tag As, Plot What Plot/Porn Without Plot, Power Exchange, Top Edelgard von Hresvelg, a little rough
Language: English
Status: Completed
Published: 2020-09-27
Updated: 2020-11-21
Packaged: 2021-03-07 20:40:18
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,275
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26683813
Author URL: https://archiveofourown.org/users/comeonlight/pseuds/notsafeforwank
Summary: "It sickens Edelgard to her core, and still this very repulsion drives her to act against everything she believes in under a weak delusion of familiarizing herself with her enemy’s tactics. The only small comfort is that said enemy knows that she knows—Rhea is in much the same position."Rheagard hatefucking because yes.
Relationships: Edelgard von Hresvelg/Rhea
Comments: 17
Kudos: 68





	1. Chapter 1

Something smells floral, not unlike the flowering bushes in the monastery gardens, blooming in all colors. A breeze carrying the scent is said to rejuvenate one’s soul, a sentiment with which Edelgard agrees. This is a time of renewal and new beginnings, or so she would like to believe. In truth the burdens of yesteryear do not melt with the winter’s snow but instead grow heavier with each passing day. The flowery scent drifting into her quarters is not that of gardenias or roses but lilies, unnaturally potent. A chill swathes her, swilling the day’s warmth that had prompted her to leave her door open and leaving naught but a familiar, unsettling sense of anticipation.

She’s here. Edelgard’s gut twists with mixed emotions, the most prominent of them being a hope that she is wrong to be tense, that Hubert has simply improved his proficiency in lurking in the shadows and is watching her from an unconventional vantage point. But Hubert is out making negotiations under the guise of shopping, and Lady’s Rhea’s soft humming is unmistakable. Edelgard bites her inner lip and brings her legs out from under her bedsheets, swinging them over the edge of the mattress in order to cross them. She sets the book in her hand to the side and takes a breath to calm herself.

She should have left the door shut.

Rhea’s step is even, her posture immaculate, and her image radiant, as always. She halts perfectly in the center of Edelgard’s doorway, sunlight framing her in a halo as she turns to face the young woman with a slight smile painted on her face. “Ah, Edelgard. I see you’re hard at work with your studies.” It’s as shallow a statement as one could make in this situation, really. Rhea has far too many eyes around the monastery not to know of Edelgard’s trips to the library in Abyss and her research of very  _ particular _ magicks. The plan to dismantle the Church of Seiros is no secret to the Archbishop; merely a nuisance that needs to be kept under control.

“Indeed I am,” Edelgard says. “Would you like to come in, Lady Rhea?” The sooner the doors shut, the better, she figures. Treating Rhea as a figure of high regard leaves a taste in Edelgard’s mouth that only becomes fouler with each interaction, and both of them know by now what will eventually come to pass. The only logic to offset the madness of it all is that one must know their enemy when waging war. One must know their enemy very, very well. It’s similar to a business relationship, Edelgard tells herself whenever she thinks too much about this woman and the insidious relationship they share. Overthinking will get her nowhere. She only needs to learn what she can of how Rhea thinks. 

Rhea takes a step into the room, her eyes narrowing with vague scrutiny. “Thinking too hard again?” She is already familiar with many of the workings of Edelgard’s mind, like a settler making herself comfortable on stolen land by using up all its resources without a care, despicably smug in her thievery. Isn’t that merely a reflection of how she’s taken over Fódlan for the ultimate goal of serving herself? The Immaculate One is the greatest sinner of all.

“If you would be so kind as to close the door behind you,” Edelgard says, evading the question. She cares not that she enunciates her words with malice. One of the few reliefs of being alone with Rhea is the lack of need to hide truths they both know.

Rhea’s lips curl, ireful but amused. She closes the door as requested, then turns the locking mechanism until it clicks. Her attention returns to Edelgard as she begins to remove her headdress. “Still plotting against me, I see.”

Edelgard’s nose crinkles at the ever-stronger scent of lilies as Rhea places the headdress on her desk. “Still spreading Pegasus excrement on your personal flowerbeds, I see.”

Rhea removes her cloak piece by piece, making herself comfortable as if she were in her own quarters. “Surely you’ve better criticisms to come at me with first thing in the afternoon,” she says as she drapes decorated cloths over Edelgard’s desk chair. “Dare I say you’re losing your edge.”

“My axe would like a word,” Edelgard quips.

Rhea shrugs the comment off. “It seems I was right to pay a visit. You seem very stressed lately, Edelgard.”

“I  _ wonder  _ why that is.”

“Well, I do imagine heresy and plotting a war would take its toll on anyone.”

“You sure don’t seem bothered by it.”

“Oh, I’m very bothered.”

The smirk on Rhea’s face suggests the opposite, though being bothered—more than bothered—makes perfect sense. Edelgard stands, annoyed. Not fuming or distressed, but substantially annoyed. Her hatred is reserved for specific people, specific acts, and specific ideas. One idea that she absolutely loathes is that Rhea can seep beneath her skin with tactics a child could master.

“...Yet here I am,” Edelgard says, stepping forward. “Plotting right in front of you.” She pushes her chair under her desk and glares up at Rhea. “And any mysterious hiccups in my plans or unfortunate accidents have brought me no harm. You never want to nip it in the bud. I’ve asked before and I’ll ask again—why is that?”

Rhea remains unfazed by Edelgard’s stare. “I’ve told you before and I’ll tell you again—you know why.” She takes Edelgard’s right hand into both of hers, and runs over the calluses with her soft fingers, far out of practice with most weaponry. “You know exactly why,” she reiterates. The mischief in her subtle expression is its own entity, twirling with merriment and coming to a rest with all its weight on Edelgard’s chest.

Edelgard’s jaw clenches. The memory washes over her like the effects of seven different poisons, peeling away the shields of her mind and forcibly opening it to weakness, to desire, to temptation. Rhea had touched her. She had touched Rhea. They’d hissed their hatred for one another breathlessly, in the throes of pleasure. And then they’d done it again, minds numb and feeble. Discipline, self-respect, gone—at the end of it all, only a disgusted longing remained. Omnipresent, inevitable, irrepressible. So they’d come together again. Touched each other. Ruined each other. Entangled themselves in a cycle that would repeat many times through today and far beyond. It sickens Edelgard to her core, and still this very repulsion drives her to act against everything she believes in under a weak delusion of familiarizing herself with her enemy’s tactics. The only small comfort is that said enemy knows that she knows—Rhea is in much the same position.

“One can never be too certain,” Edelgard challenges. “Tell me. Why have you not come for my head?”

Rhea sighs with a flicker of annoyance in her eyes. She takes a lock of white hair between her fingers, examining the strands rather than Edelgard’s scowl. “Simply put, Edelgard von Hresvelg: I am not finished with you.” Her words are as snow: soft but frigid, melting on Edelgard’s skin. The chill shines in Edelgard’s eyes like crystals of ice in sunlight as she swats Rhea’s arm away. The two share a glare, neither conceding in a battle as trivial as a staring contest. Were Edelgard in her right mind, she would deem the interaction childish. Her right mind and Rhea’s presence, however, can no longer coexist.

“Are you satisfied?” Rhea asks, unflinching before eyes that see red—burning, bloody, wrathful red.

Edelgard clenches the white fabric covering Rhea’s chest in her fist and takes a half-step forward, reducing the small gap between them to virtually nothing. “Never,” she growls, and an unsettling twinkle appears in her adversary’s eyes.

“Is this your attempt to intimidate me?” Rhea inquires with a slight tilt of her head.

Edelgard replies with a smirk befitting a madwoman; admittedly, it would not be inaccurate to say that Rhea has in fact driven her mad in a sense. “Nonsense. The likes of you are far too arrogant to be intimidated.” She brings her fist down, pulling the top of Rhea’s dress until the skin beneath spills out. Rhea lifts her brow with more intrigue than surprise, and, as Edelgard has learned to identify by now, anticipation that eerily mirrors her own.

“Is that so? Then, that makes two of us.”

A biting kiss reminds Edelgard in painfully vivid detail just how deep this addiction runs. Her hands move as if possessed, clawing at Rhea’s dress with a neediness that could tear the fabric apart—if only she could tear Rhea herself apart. Edelgard’s scrambled thoughts pursue a possible logical reason for Rhea to feel so warm under her hands, so soft against her lips, but the search is helpless in the wake of the ravenous urges that move her body like a puppet. She doesn’t know. She doesn’t care. She can’t care. Edelgard’s conscience revels in the unfolding lunacy, in the anticipation of defiling the Church’s beloved Archbishop, in the feeling of Rhea’s tongue gliding under her own in a senseless and excessive exchange of saliva that drips down their chins.

As her dress falls, Rhea pulls Edelgard’s head closer into even more fervent kisses, almost as if she means to devour the young woman. On a different day Edelgard would’ve allowed it, would’ve let Rhea cover every inch of her skin with the marks of her tongue, teeth, and hands; claimed and trained and ravaged until she could no longer manage any act but to tremble with sick satisfaction. But not today.

Oh, she should have left the door shut.

Edelgard lifts Rhea by the hips, and pivots to pin her high on the wall. The move visibly catches Rhea off guard, granting a fleeting sense of contentment. Invariably, this small sense of gratification causes Edelgard to crave more. She looks up with impatience at a rather curious Rhea, who simply stares back, then sighs. Rhea lifts her knees to rest over Edelgard’s shoulders as Edelgard keeps her back up against the wall, strong palms and fingertips sinking into her rear with a purposeful squeezing motion. Apparently pleased with Rhea’s adjustment, Edelgard’s eyes fall to the tuft of green hair directly before her, then dart back up. “Are you going to tell me what this is, hm?”

“Whatever do you mean?” Rhea asks, self-satisfaction rolling off her tongue.

“You’d do well to wear some fucking underwear in public,” Edelgard spits. She snarls, pressing her nose to Rhea’s mound as she adjusts her angle. As always, Rhea’s scent is as indescribable as it is intoxicating. Inhuman. Edelgard uses the flat of her tongue to lap up what dribble there may be—and who would’ve guessed, Rhea is soaking wet. Of course she is. The wretch is insatiable. Edelgard would hiss words of contempt if not for her own unquenchable thirst for every last droplet of Rhea’s arousal pushing her to suck and lick every last bit of her. Rhea’s sighs and Edelgard’s grunts form an off-beat, incongruously aggressive mix representative of their relationship. It makes Edelgard want to tear Rhea’s throat out more than she already did before. But if she tore Rhea’s throat out, she wouldn’t be able to hear the satisfying cries of the Archbishop as she crumbles in a fit of pleasure. These thoughts come and go as Edelgard incessantly circles Rhea’s clit with her tongue, then sucks on it with all the attentiveness she can manage, then again returns to messy, erratic circles.

Rhea tilts her head back against the wall, lips parted as she whimpers. Her hands clutch her breasts, fingertips pressed to erect nipples. The muscles of her legs tighten and relax, like they’ll either fall off Edelgard’s shoulders or wrap around her neck at any given moment. Rhea would just  _ love  _ to extinguish a life in such a way, Edelgard imagines, almost expecting it now, but it doesn’t come. As she gorges on Rhea’s taste, said woman’s moans gradually become more prominent. She’s been waiting for this. She’s been waiting to just show up and take what she wants. The entitlement is sickening. The moment Rhea’s voice cracks, Edelgard turns from the wall and drops her onto the floor with a giggle drowned out by the thud.

“You…” At last, Rhea’s rage rears its ugly head with a monstrous growl as Edelgard drags her by the leg and forces her onto her stomach. She could put up a fight, Edelgard thinks. Rhea could put up a fight but she just  _ doesn’t,  _ like she’s eagerly awaiting further defilement. And why wouldn’t she be? The twisted woman’s sexual perversions are merely the tip of the iceberg of her wicked desires. Her sins call for retribution that would take lifetimes to carry out. While it is impossible for Edelgard to deliver proper punishment in full with her own two hands, she can at least remind Rhea—remind her of the corruption that she craves as much as she spreads.

“Stop me,” Edelgard taunts, one hand pressing on the back of Rhea’s shoulder and the other gripping the soft flesh of her behind. What a perfect body; the ethereal picture of deceit. Disgusting, disgusting, disgusting,  _ disgusting, disgusting.  _ The scent of lilies in her hair is disgusting. Her defined muscles and flushed, supple skin are disgusting. Her shuddering breaths are disgusting. The arousal dripping from between her legs, the very same arousal lingering on Edelgard’s lips and tongue is  _ disgusting. _

_ “Stop me,”  _ Edelgard spits again. She strikes Rhea’s rear with her palm in an outburst of several kinds of frustration. Her finger, in spite of fleeting hesitation, slips between Rhea’s cheeks and curls, the very tip prodding ever so slightly into swelling heat.

“You wouldn't dare,” Rhea breathes, squirming in a factitious attempt to escape the situation. Edelgard can hear the smile in her voice. Those words are a challenge, simply put—one that Edelgard is loath to back away from. Granting Rhea the pleasure of asserting authority over her would be even more intolerable than sating her putrid lust.

What a nuisance. She should have left the door shut.

The wounded, ecstatic wail of a masochist rings in the air as Edelgard presses into Rhea, searing heat gradually devouring her finger. Rhea has nothing to say now; nothing but low groans of bliss even as she bleeds onto Edelgard’s finger. Is this all it takes? A single finger impetuously—no, malevolently—thrusting into her to knock Rhea off her high horse? It’s disappointing. It’s pathetic. “You're _pathetic,”_ Edelgard scathes as her own body burns, waiting for Rhea to shatter under her, to just come, _come already._ “Come. What are you waiting for? _Come!”_ The demand, though from Edelgard’s mouth, drips with Rhea’s poison. Her madness. And maybe the satisfaction of that simple fact is what pushes Rhea over the edge.

Rhea’s body tightens to a full lock, her only movement a slight tremble as time comes to a halt. Satisfaction splits Edelgard’s face into a contorted grin that Rhea won’t see, the triumph more fulfilling than a mere orgasm. Isn’t it? Should they find out? Edelgard pushes these questions and other, less relevant thoughts from her clouded mind as Rhea’s muscles relax, and the elder woman gives a final sigh of pleasure.

It’s done. If it’s a competition, Edelgard has won this round. But just this round. Next time—and there will be a next time—they’ll start over again in their petty clash of wills and malice and hunger. And they’ll love every second of it. And they’ll hate, with an unfathomable passion, every second.

“I'll kill you someday,” Edelgard mumbles numbly. She will. She must. This weakness is too great to be overlooked. She’ll kill Rhea with her own two hands. Someday. But as things stand, that day won’t be anytime soon.

**Notes for the Chapter:**

> I wasn't sure I'd ever post this, honestly. But I managed to finish it after letting it sit on the backburner for a few weeks. This was fun to write. Getting back into smut while exploring this interesting pair... Anyway. Let me know what you think. And if you like, follow [my fic account on Twitter](https://twitter.com/ruingazzz) where I basically just cry about ships and occasionally vomit headcanons.


	2. Chapter 2

**Summary for the Chapter:**

> Part II: A Lesson in Truth. Or something.  
> On a completely different occasion, Edelgard follows Rhea to her bedchamber for reasons they both know, regardless of how willing Edelgard is to admit it. An exchange of power occurs. Sub!Edelgard. Rhealeth and one-sided Edeleth mentions.

“You’re nothing but a petulant child who can’t decide what she wants.” Rhea scrutinizes Edelgard with a smirk on her face, satisfied with her deprecatory remark. Maybe it’s hypocritical of her to find satisfaction in belittling the pest who’d followed her to her bedchamber. Maybe it’s too late in the evening to care. “What will it be tonight?” Rhea runs a hand through her hair, still damp from a hot bath. “Are you here to attempt assassination? Or were you hoping to satisfy that twisted little desire of yours?”

Edelgard stands stone-faced by the door, outwardly unaffected by Rhea’s words. In all ways but literal, she’s put up a mask; and that just won’t do. It won’t do at all. Still, Edelgard’s silence can be taken as an advantage. Her silence is proof of the indecisiveness Rhea had spoken of, and by extension a lack of control. “Edelgard, won’t you answer my question?” Rhea takes a seat at the edge of her bed and crosses her legs, leering all the while. She may have her fun yet—Edelgard’s indifferent expression gives way to a slight glower.

“Disaster of a girl,” Rhea scoffs. “I’ll help you sort it out.” She beckons the newly-crowned Empress with her fingers. “Come here.” Of course, Edelgard doesn’t move a muscle, so Rhea tries wording it differently: “Come now, really. I won’t bite, dear Edelgard.”

“I trust that statement as far as I could throw the Immaculate One,” Edelgard replies flatly. But she does come, her stride even as she leaves the locked door behind. She plants her feet in front of Rhea’s, placing the two of them just under an arm’s length apart. They’re close enough for a private conversation, and plenty close enough for a standard blade to do its work. The temptation to sink silver into soft flesh makes itself apparent in Edelgard’s gaze, and Rhea can’t help but feel tickled as the girl quietly tells her, “I could choke the life out of you.”

There it is. That warped, ireful attraction that neither of them can deny. The violent words sound so cute coming out of that haughty mouth of that Rhea can’t help but find it hilarious—and to help herself. “It seems we both have a strained relationship with the truth,” Rhea says with a sigh. She shifts her weight to her feet and rises to her full height, not that much taller than Edelgard herself but just tall enough to look down at her, and that tiny gesture makes the lively little flame of joy burning inside crackle with anticipation. “So, this is what you want tonight,” Rhea says in a near whisper as she lifts her hands to Edelgard’s neck.

Edelgard swiftly steps back, glaring. “Do not mistake your sick intentions for my desires.”

“So you do in fact have desires,” Rhea retorts. “Desires involving myself? The Archbishop? How unbecoming.” She steps to Edelgard, and lays her fingers across the fabrics decorating the Empress’s chest. “You wish to dismantle my Church and take me as a prize for your own self-satisfaction? Is that it? Or is it that you seek respite from all the power you now hold?” There it is. The spark of frustration in Edelgard’s eyes that emerges when she’s been seen through. The word “respite” lingers in the silent room as Rhea grins from ear to ear.

“So what?” Edelgard asks, to which Rhea roars with laughter.  
“You know what! Or you wouldn’t have come here.”

Rhea takes one step back and sits once more at the edge of her bed, endless amusement dancing in her eyes. “I’m happy to give you what you seek, dear, if you’ll let me have my fun. So, do we have a deal?”

“Just this once,” Edelgard lies with a nod and no protest, the audacity of those words only adding to Rhea’s mirth.

“Wonderful. Now, remove those atrocious garbs. Show me everything.” On its own, Edelgard’s scarred, muscular body is a familiar sight. The actions it takes once bare—those are where Rhea’s delight blossoms. Edelgard strips away her cape, her ascot, her gloves, every sign of her status; the garments fall one by one into a pile of gold, black, and red until at last even the ribbons that match her eyes join them, freeing white tresses of hair that fall upon her shoulders and back. Rhea had asked. Edelgard has delivered. This, Rhea notes as she speaks once more, is where her fun begins: “Look at me.”

Edelgard had closed her eyes as she removed her uniform, maintaining a weak illusion of calm. Her body, however, had never been a liar. Her nipples stand erect, and red burns under her pale skin all over. Rhea hums, indulged by her adversary’s obedience. Edelgard opens her eyes, the blush deepening as she glares straight forward. Rhea responds with a sigh. “So flustered. I suppose that much can’t be helped. We may as well have fun with it, no?” To that end, she issues another command. “Come, sit.” Instead of motioning to the abundant space on either side of her, Rhea spreads her legs and runs her hand over the stretched space of her immaculate white dress.

Edelgard mutters a word under her breath, but obeys all the same. The way she contradicts herself fascinates Rhea as much as it infuriates her. Bemusing—that describes their fatal attraction to one another quite well. Edelgard takes the seat provided to her, bare back against Rhea’s chest and the presence of danger assuredly stirring in her gut. “I told you I wouldn’t bite,” Rhea whispers against Edelgard’s shoulder as she brushes away locks of hair. “But I’m afraid I must withdraw that statement.” A pair of fangs grazes hot skin with care as Rhea’s hands situate themselves over Edelgard’s exposed breasts.

“Expected,” Edelgard mutters as she flinches. She grips her knees as Rhea toys with her nipples, exploiting their sensitivity with pinches and pulls. Rhea simply chuckles, and retracts her fangs to replace them with her lips and tongue. She makes a deliberate, slow line toward Edelgard’s neck, sprinkling it with questions.

“Do you touch yourself, Edelgard? Oh, but of course you do.”

“What do you think about when you touch yourself? Is it the Professor?”

“Do you know about what the Professor and I do together, on nights just like this?”

“Shut up,” Edelgard hisses immediately before her breath hitches. A shiver crawls up her spine and shakes her whole body, as if her words had instantaneously backfired and hushed her without Rhea moving a muscle.

“Would you like me to tell you about it?” Rhea continues. “The recollections are a treat, I assure you.” She nuzzles the back of Edelgard’s neck and plants a gentle kiss. “Touch yourself for me, dear, and I’ll tell you all about our wonderful Professor.” Her hands slide down Edelgard’s torso, then reach out to pry her fingers from her knees. “Just like this,” Rhea says, her voice soft as she moves Edelgard’s hands between her thighs. Silently compliant, Edelgard begins to rub herself slowly. “Good girl,” Rhea whispers. “Now, let me tell you all about her.”

Edelgard bites her lip as the rhythmic up-and-down movement of two fingers along her lips lightly massages her clit. “She’s quiet,” Rhea tells her. “She hardly moans when I touch her. But every gasp, every little whimper that I can get out of her is… Ah, I’m getting excited.” Edelgard herself is struggling to keep her voice in check, and the fact is quite clear. “You’re not quiet at all, Edelgard, are you? You can drop the poor act. It can’t get more embarrassing than this, can it?” Rhea’s hands return to Edelgard’s breasts, squeezing them with equal fondness and ravenousness. “And, I love hearing you.” That much is true—the pathetic sounds that come out of Edelgard’s mouth when she’s trembling with pleasure are titillating to put it mildly. This peculiar bond of hatred really is endlessly amusing.

Her fingers now moving in circles, Edelgard whimpers with the rapture of physical stimulation and the tales of nights past whispered against her skin. “She never breaks eye contact. I remember just days ago, her perfect body shuddering against mine. Her eyes were so beautiful as she came…” Rhea sighs contentedly while Edelgard’s breaths become louder. “The Professor is accommodating as well. It’s no surprise.” Smiling lips suck on Edelgard’s neck, decorating it with tiny bruises between each sentence.

“She’s happy to spank me when I’ve been misbehaving.”

“You’d love that, wouldn’t you, dear Empress?”

“You needn’t worry. I’ll take care of all that and more.”

The soft-spoken words prod Edelgard ever closer to the edge as she mindlessly rubs herself into bliss. Her arrogance and anger have all but dissipated as she succumbs wholly to the perversions of both herself and her abhorred lover. Just like last time. Just like next time. “I’ll let you come this time. Be sure to give thanks.”

“Thank you,” Edelgard promptly replies, her words nearly hollow as her mind embraces the clouds it’s found itself in. She calls out in a moment of carelessness, her muscles all tensing—“Rhea!”—and euphoria claims her. Rhea simply enjoys the treat of having such a spectacle occur in her lap, grinning to herself as Edelgard rides her high.

“No penetration needed,” Rhea observes. She rests her hands on the bed and relaxes her posture while Edelgard sits stiff, presumably collecting herself. “In the end, the name you called out…”

“I meant to say ‘Professor!’” Edelgard hastily asserts.

Rhea gives a blank stare to the scars on Edelgard’s back. “Of course you did.”

  
There are some situations in which her adversary’s ability to lie simply does not carry over.

**Notes for the Chapter:**

> I didn't plan on writing a part two to this, but then it happened. As good a way to get back into the groove of writing as any, right? Writing this was certainly an interesting experience. Experimentation, yay!


End file.
